Mass data storage libraries contain and store many media such as optical disks, magnetic disks, or tape cartridges containing huge amounts of information or data embedded thereon. The media typically bear identifying indicia such as barcodes on a surface of the media so that information embedded in the media may be associated with the indicia and so that the location of and an inventory of the information in the media within the library may be maintained in a computer-based memory for inventory management. The libraries typically employ robots that are designed to move within the library and to transport the media between their storage locations and a drive that is designed to read information from or write information onto the media. A host computer having an associated operator input, such as a keyboard or a touch screen, is used to issue commands to the robot and to the drive so as to coordinate and implement the library functions of storing the media in selected locations and reading information from and writing information onto the media via the drives.
The host computer may communicate with the memory, the robot, and the drive to facilitate library operations. So, for example, the library operator may wish to read certain information embedded in one of the media. The computer-based memory will know in what media that information is embedded and will know where in the library the media containing that information is located for storage. The host computer may then instruct the robot to move to a location where the desired media is stored, grab the media, move the media to the drive, and then insert the media into the drive. The host computer may then display the information read by the drive that is embedded in the media disposed within the drive. A reverse process may be used to return the media back to a particular storage location in the library.
In relatively large mass data storage libraries, the media can be contained in removable, transportable magazines. The magazines are somewhat like trays in which the media typically stand upright and usually such that the identifying indicia associated with each media is presented on an upper or outer, exposed surface. Often a magazine contains media embedded with associated, related information.
In these larger library systems, a robot may transport the entire magazine containing the media to a particular storage location, although when implementing read or write operations, the robot will still select a single media from the magazine before transporting the media to and inserting the media into the drive. As such, the magazines themselves also typically bear identifying indicia, such as a barcode on an outer, exposed surface.
When magazines containing media need to be placed into the library or taken from the library, modern libraries utilize a so-called input/output or import/export station through which the desired magazines may be placed into or removed from the library. These I/O stations are used so that there is no need to perform a complete re-inventory of the media stored in the library and so that library operations via the robot and the drive may continue without interruption. When an operator places a magazine into the I/O station, it is important that the magazine is properly positioned so that the identifying indicia can be properly scanned into the library memory for inventory management, and so that the robot may properly grasp the magazine and transport the magazine to its designated storage location. If a magazine is improperly positioned in the I/O station, then the process may be halted, resulting in down time of library operations, or more severely, might result in damage to the magazine or the media contained therein or result in malfunctioning of or damage to the robot.
The present invention was developed in the context of this background.